JPH02269894A - Guide roller for multihole belt, such as drying wire cloth of paper-making machine - Google Patents

Abstract

PURPOSE: To prevent the deformation of an air guide box due to the temperature difference between blowing air and suction air by axially shifting the two air chambers of the air guide box relative to each other. CONSTITUTION: Two air chambers for blowing air and suction air, respectively, are formed by the internal space of an inside tube 41 and the annular space 39 between the inside tube 41 and an outside tube 42. A support tube 421 and the inside tube 41 are mutually superposed so that the inside tube 41 is movable axially, and the inside tube 41 is allowed to slide along the outside tube 42 by the aid of a discrepancy bolt 44 and the flange of a tube portion 45.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a guide roller for a perforated belt according to the preamble of claim (1).

[Conventional technology]

Guide rollers of this type are known (see US Pat. No. 4,510,698 and TAPPI Journal, September 1987, page 9-69, Figure 1O). Considering their function, these guide rollers are also called suction-blow rollers.

The purpose of these guide rollers is, for example, to supply fresh air to the pockets of the twin screen drying section of a paper machine and, at the same time, to
Its purpose is to suck out air that contains a lot of water vapor. This is an attempt to avoid flow across the pocket, flapping of the web edges, and asymmetry of the wetting cross-section (see TAPPI, page 67, "Pocket ventilation"). These problems become more pronounced the higher the operating speed of the machine, such as a paper machine.

In particular, there is a blow-out zone in the area on the entry side of the guide roller and a suction zone in the area on the exit side, but the reverse arrangement is also possible.

The blowing air is preheated in such a way that the blowing air fed to the perforated belt and thus, for example, the drying screen of a paper machine, can absorb as much water vapor as possible. In contrast, the temperature of the air drawn in is lower.

Thus, the actual blown air and the drawn air have very different temperatures. This temperature difference can range from 30° to more than 40° and is particularly significant when the entire device is restarted from a cold state or after a web break. When the web, especially the paper web, has not yet passed through the drying section,
For example, even while the paper machine is starting to run, the temperature differences are large and, in some cases, the distribution is not uniform.

The above temperature differences can cause deformation and tension in the air guide box of the guide roller. As a result, wear and/or destruction of the sealing members separating the blowing zone and the suction zone from each other occurs.

[Problem to be solved by the invention]

The problem on which the invention is based is that deformations of the air induction box due to temperature differences between the blown air and the sucked-in air are avoided to a large extent and the size of the blown-out and sucked-in zones is limited.

The purpose is to show a guide roller of this type with a greater number and arrangement of possibilities than before. In other words, the purpose is to and/or to show a guide roller that is better adapted to different usage situations).

[Means and effects for solving the problem] According to the core concept of the invention, this problem is solved by making it possible for the two air chambers of the air induction box to be offset relative to each other in the axial direction. Ru.

A structural solution is to arrange the two air chambers of the air induction box separately and next to each other (so that they can extend longitudinally independently of each other), for example by using tubes with a semicircular cross section. It is conceivable to form it from a part of.

A better solution to the problem presented is claimed in claim (3)
According to two mutually coaxial tubes with different diameters,
One is inserted into the other so that they can extend longitudinally independently of each other as different air temperatures develop. This avoids deformations of the air-conducting box and at the same time ensures that the outer tube, which carries the sealing element for the section of the annular space on the outside, has an equal temperature over the entire inside. In this way, the risk of wear of the sealing elements previously present is largely or almost completely eliminated. Moreover, such a coaxial arrangement of the air chambers offers a large number of possibilities for arranging the blowing and suction zones around the guide rollers, as will be explained further below.

Various variants and special configurations of the guide roller of the present invention include:
Subject to dependent claims.

〔Example〕

Hereinafter, the present invention will be explained in more detail based on the drawings.

The guiding roller 1 (or "suction-blowing roller") shown in FIGS. 1 and 2 has a perforated rotating roller sleeve 2 and a stationary air-guiding box 3. FIG. The roller sleeve 2 has a journal 5 at both ends of the roller.
The journal is closed by a flange cover 4 with a roller bearing 7, which is journalled in the base 6. The bearing is fixed to the stand, and the cover 8 has a through hole 9.

The air guiding box 3 is constructed from two tubes of different diameters, one inserted approximately coaxially into the other, i.e. an inner tube 4.
1 and an outer tube 42.

The diameters of the inner tube 4, the outer tube 42 and the roller sleeve 2 are selected in such a way that there are three sufficiently large air spaces for the air supply conduit and the air discharge conduit. Here, the two air chambers for blown air and intake air are formed by the inner space of the inner tube 41 and the "inner annular space" 39 located between the inner tube 41 and the outer tube 42. (Outer tube 42
In the "outer annular space" 43 (between the roller sleeve 2 and the roller sleeve 2), various zones are formed, among which a suction zone S
and a balloon zone B. For this purpose, several, for example four, longitudinal sealing elements 60 to 63 are provided, which are fixed to the outer side of the outer tube 42 and which cover the inner side of the rotating roller sleeve 2. Glide. Furthermore, at both ends of the outer tube 42, circumferential sealing members 18 are provided which laterally delimit the outer annular space 43.

The inner tube 41 is coaxial with the roller sleeve 2, and at one end of the negative roller the flange cover 4 and the bearing have a passage through the cover 8 to or from the outside. Outer tube 42
is likewise coaxial with the roller sleeve 2 and has a coaxial passage to and from the outside as well at the other end of the roller. The outer tube 42 is supported on the inner tube 41 via several suspension ports 44, which are distributed around the circumference and length of both tubes. Furthermore, the inner tube 41
In order to connect the interior space of the tube with the outer annular space 43, a cross passage in the form of a tube section 45 is provided.

These tube sections 45 are fixed to the inner tube 41 and rest axially movably on the outer tube 42.

For this purpose, each tube section 45 has a flange, via which it rests on the edge of the corresponding bore 99 in the outer tube 42. In particular, a sealing disk 98 is fitted between the flange and the edge of the borehole 99 of the outer tube 42. The diameter of perforation 99 is significantly larger than the outer diameter of tube section 45. The sealing disc 98 is soft and therefore susceptible to flexing when lateral displacement of the tube section 45 occurs.

With this guide roller 1, it would also be possible to operate the inner tube 41 as a suction air chamber and the outer tube 42 as a blowing air chamber. In this case, the inner annular space 39
Blow air is supplied to the outer pipe 42 and sent to the annular space 43 through the opening 400 of the outer tube 42 and from there to the roller sheathing 2.
will be blown out through the perforations 16. Furthermore, the intake air is perforated 16. Tube section 45 and inner tube 41
It will flow outward through the In the illustrated embodiment, the reverse is true, with the inner tube 41 serving as the blown air chamber.
The outer tube 42 is operated as a suction air chamber.

The outer tube 42 is connected at either end, via the conical intermediate section 20 or 21, to a support tube 420, 421, which passes through the journal 5 and whose bearings rest in the cover 8. The support tube 420 (on the right side of the figure) is open towards the inner annular space 39 .

The suction air thus flows from the outer annular space 43 through the opening 400 (in the outer tube 42), through the inner annular space 39 as well as the support tube 420, and through the perforation 9 into a suction conduit (not shown).

The other support tube 421 of the outer tube 42 is open towards the inner tube 41 and serves as a supply conduit for the blown air, which is conveyed from the inner tube 41 via the tube section 45 into the outer annular space 43. reach The inner tube 41 is closed at the other end by a cover 22, for example conical. Support tube 421
and the inner tube 41 overlap each other so that the inner tube 41 is movable in the axial direction. At that time, the inner tube 41 is connected to the suspension bolt 4.
4 and flanges of tube section 45 to slide along outer tube 42.

The blowout zone B formed in the outer annular space 43 is
Regarding the length of the guide roller 1, it is possible to divide it into several partial blowout zones. This is done, for example, by means of several additional circumferential sealing elements 46 arranged between two tube sections 45 in each case. Thus, for example, four partial blowout zones B, B2. B3. B4 is obtained.

Correspondingly, the inner tube 41 is divided by a dividing wall 47 into four subchambers, each of which can then be connected to its own blown air supply. In this way, different amounts of blown air are supplied to the partial blown zones,
For example, the wet cross section of the paper web can be influenced.

FIG. 2 shows a guide roller l in a so-called double screen drying group of a paper machine. The paper web 50 to be dried now leaves the first drying cylinder St and runs onto the second drying cylinder 52. From this second drying cylinder 52 the paper web 50 is transferred to the third drying cylinder 5.
Sent to 3.

The paper web 50 is then pressed against the sleeve surfaces of the first and third drying cylinders 51 and 53 by the drying screen 49. On the way from the first drying cylinder 51 to the second drying cylinder 52 and the second drying cylinder 52
On the way from to the third drying cylinder 53, the paper web 50 runs without contacting the drying screen. In the area of the "pocket" (delimited by the three cylinders 5, 52, 53 and the paper web 50) the drying screen passes from a first drying cylinder 51 via a guiding roller l to a third drying cylinder. Drive to 53. The drying screen is then wrapped around approximately half of the circumference of the guide roller 1.

FIG. 2 further shows that a blowing zone B is defined in the outer annular space 43 by two longitudinal sealing members 60 and 61, which blowing zone B is connected to the inner tube 41 via a tube section 45. It is shown that. The arrangement of the longitudinal sealing members 60 and 61 is such that a part of the blowing zone B is located before the position where the drying screen 49 reaches the guide roller.
Some are performed later than the position. In other words, the blowing zone B extends approximately symmetrically with respect to the point where the drying screen 49 reaches the guide roller 1.

In the blowout zone B, an air induction box 3 is installed in the direction of rotation.
There continues to be a so-called blockade zone SZ that has no communication with the interior of the area. Next follows the suction zone S, which is defined by the longitudinal sealing members 62 and 63 and communicates with the inner annular space 39 via the opening 400. The suction zone S is considerably larger than the blowout zone B and ends at the point where the drying plow 12I49 leaves the guide roller 1. The closure zone SZ is thus closer to the first cylinder 51 than to the third cylinder 53. At the same time, the distance between the blocking zone SZ and the second cylinder 52 is arranged to be smaller than the distance between the blocking zone and the first cylinder 51. Due to the blockade zone SZ, the blowout zone B and the suction zone S are no longer directly adjacent to each other. By spatially separating the blowout zone from the suction zone in this way,
Direct air exchange (short circuit) between these two zones is prevented. The blown air thus supplied reaches the more remote areas of the pocket first, so that it has a greater chance of receiving water vapor before being sucked back in by the suction zone. It is self-evident that the remaining part of the annular space 43, which falls within the open circumferential part of the roller and lies between the longitudinal sealing members 63 and 60, does not communicate with the interior of the air-guiding box 3.

FIG. 3 likewise shows a paper web 50 running from a first drying cylinder 51 via a second drying cylinder 52 to a third drying cylinder 53. In contrast to FIG. 2, the guide roller l° is offset in the direction of the first drying cylinder 51, so that the paper web 50 (on the way from the first drying cylinder 51 to the second drying cylinder 52) is first dried on a screen. 49 to the guide roller 1°,
From there it then travels to the second drying cylinder 52 without contacting the drying screen. This travel path of the paper web 50 from the first drying cylinder to the second drying cylinder can be fairly straight, as shown, but it can also be different. The drying screen 49 wraps around approximately half the circumference of the guide roller and then runs to the third drying cylinder 53.

The air guide box 3 of the guide roller l° also consists of two tubes of different diameters, one inserted approximately coaxially into the other, namely an inner tube 41 and an outer tube 42.

In FIG. 3 (in contrast to FIG. 2) the internal space of the inner tube 41 is an air chamber for suction air, and at the same time (in contrast to FIG. 2)
The inner annular space 39 (between the outer tube 42 and the outer tube 42) is the air chamber for the blown air. The outer annular space 43 (between the outer tube 42 and the roller sleeve 2) is again divided into various zones by several longitudinal sealing elements 60 to 63.

For the guidance of the paper web 50 and the drying screen 49 shown in FIG.
(traveling from) to the point where it reaches the guide roller.

This creates a constant negative pressure in the wedge-shaped space Z.

The air boundary layer thus carried from the drying screen into this wedge-shaped space Z is sucked off by the suction-blowing rollers. As a result, an air boundary layer flows past the drying screen 49 in the region of the wedge-shaped space Z, avoiding premature removal of the paper web 50 from the drying screen. The suction zone S is defined by two longitudinal sealing members labeled 60 and 61.

Furthermore, two longitudinal sealing members 62 and 63 define a blowing zone B. Between the suction zone S and the blowout zone B there is a closed zone Sz which does not communicate with the two air chambers. The blowout zone B is considerably larger than the suction zone S in the circumferential direction. This allows a sufficient amount of dry blown air to be supplied to the pockets defined by the drying screen 49 running via the second cylinder 529 paper web 50 and the guiding roller 1. The supplied dry air becomes enriched with water vapor in the pockets, and then a portion passes through the drying screen 49 and is discharged upwards (arrow 70).

Some move away from the pocket laterally.

Figure 4 shows the same drying cylinders 51, 52 and 5 as in Figure 3.
3, arrangement 9 of the guiding roller 1'' shows the guiding state of the paper web 50 and the drying screen 49. However, the internal structure of the guiding roller l'' is different. 1st
As shown in FIG. 2, the inner space of the inner tube 41 guides the blown air, and the inner annular space 39 discharges the sucked air. In this embodiment, the balloon zone B is
It is divided into partial blowout zones in the length direction.

Correspondingly, the internal space of the inner tube 41 is divided into several subchambers by partition walls 47. Each of these subchambers is supplied with an individually controllable amount of blown air from the outside. In this way, the drying cross-section of the paper web 50 can be influenced.

Another difference between FIG. 4 and FIG. 3 is that in addition to the suction zone S there is an additional suction zone S'. Additional suction zone with 1” guided roller
It is located in the second inner quadrant of the winding drying screen 49. The blowing zone B is somewhat smaller than in FIG. 3 and is located in the first inner quadrant of the winding of the drying screen 49 of the guide roller t'. On both sides of the balloon zone B -
There are two containment zones SZ or SZ'. This additional suction zone S' allows a portion of the supplied dry air, which has become enriched with water vapor, to be discharged again through the suction-blowing roller. Thus, the embodiment of FIG. 4 allows better control of the humid air discharge than with the arrangement according to FIG.

The guiding conditions of the paper web 50 and of the drying screen 49 shown in FIGS. 3 and 4 are known per se from US Pat. No. 4,694,587.

From this specification, using a blowout box, the drying screen is placed in the wedge-shaped space where it reaches with the paper web onto the guiding roller.
It is known to create negative pressure.

This ensures that the paper web adheres to the drying screen and also seeks to control the movement of air in the pockets mentioned above. This object according to the invention is
This can be achieved without the need for the above mentioned speech bubble box.

〔Effect of the invention〕

As described above, according to the present invention, it is possible not only to effectively avoid deformation of the air induction box due to the temperature difference between the blowout air and the suction air, but also to reduce the size, number and installation position of the blowout zone and the suction zone. can be selected more freely, and a guide roller that can be well adapted to different operating conditions can be provided.

[Brief explanation of drawings]

FIG. 1 shows a first embodiment of the guide roller (I-I in FIG. 2).
2 is a cross-sectional view of the guide roller of FIG. 1 arranged in a double screen drying group of a paper machine; FIG. 3 is a second embodiment of the guide roller cross-sectional view of
FIG. 4 is a cross-sectional view of a third embodiment of the guide roller. , 1', 1'...Induction roller, 2...Roller jacket, 3...Air induction box, 4...Flange cover, 5...Journal, 6...・The bearing is a stand, 7... Roller bearing, 8... The bearing is a cover, 9... Through-hole, to, 1, 12, 60, 6, 6
2゜63... Longitudinal sealing member, 16.99... Perforation, 18.46... Circumferential sealing member, 20.21...
...Middle part, 22...Cover, 39.43...
- Annular space, 41... Inner tube, 42... Outer tube, 44... Suspension bolt, 45... Pipe portion, 47
...Partition wall, 49...Drying net, 50...
Paper web, 51, 52゜53... drying cylinder,
98... Sealing disk, 400... Opening, 420,
421...Support pipe, B...Blowout zone, B
l, B2. B3. B4... Partial balloon zone, s
, s'...Suction zone, sz, sz'...
... Blockade zone, 2... Wedge-shaped space.

Claims (16)

[Claims] (1)a) A stationary hollow air-guiding box (3), around which the perforated roller jacket (2) rotates, extends over the entire length of the guiding roller (1) and has one end for directing the blown air. One for blowing out (blowout zone B) and the other for sucking and discharging air (suction zone S).
b) there is an annular air (39, 43) between the air guiding box (3) and the roller sleeve (2), which air annular is connected to the longitudinal sealing member (11, The longitudinal sealing member (11, 12, 13; 60, 6) is divided into a blow-off zone (B) and a suction zone (S) by
1) for the production or processing of perforated belts, such as in particular webs, such as paper webs, characterized in that they are arranged in an air-guiding box (3) and are adapted to rest against the inside of the roller sleeve (2) Guide roller for mechanical drying screen, characterized in that: c) the two air chambers of the air guide box (3) are able to be offset relative to each other in the axial direction. (2) Claim (1) characterized in that the air chambers, when viewed in cross section, form part of circles that substantially complement each other, in particular forming a circle. induction roller. (3) a) The air-guiding box (3) consists of two tubes arranged approximately coaxially, one in the other, i.e. the outer tube (42).
and an inner tube (41); b) an inner annular space (39) between the outer tube (42) and the inner tube (41) provides one air chamber to the inner tube (41); the inner space forms the other air chamber; c) the outer annular space (43) between the roller casing (2) and the outer tube (42) has some space with the inner space of the inner tube (41); are connected via transverse passages (tube sections 45), and are characterized in that these transverse passages (tube sections) allow the outer tube to be displaced in the axial direction with respect to the inner tube. , the guide roller according to claim (1). (4) The inner annular space (39) is the blowout zone (B)
In this case, the inner space of the inner pipe (41) is a suction zone (S).
Guide roller (FIG. 3) according to claim 3, characterized in that it is associated with. (5) The inner annular space (39) is the suction zone (S)
In this case, the inner space of the inner tube (41) is a blowout zone (B).
A guide roller according to claim 3 (FIGS. 1, 2 and 4), characterized in that it is associated with, respectively, a guide roller (FIGS. 1, 2 and 4). (6) the outer tube (42) extends towards the inner tube (21);
Any of claims (3) to (5), characterized in that a suspension bolt (44) is provided that abuts the inner tube (41) so as to be able to shift in the axial direction. Induction roller described in Crab. (7) The blow-out zone (B) has several circumferential sealing members (
46) parallel to the axis by a series of partial blowout zones (
B1, B2, B3, B4), and correspondingly, the air chamber associated with the blowing zone (B) is divided into partial chambers by a partition (47), and these partial chambers A guide roller, characterized in that it can be connected to a separately controllable blown air supply pipe. (8) a) a guiding roller (1) is arranged between the first, second and third drying cylinders (51-53);
The paper web (50) to be dried runs through these drying cylinders one after another and passes through a drying screen (49).
presses the paper web onto a first and a third cylinder and runs between these cylinders via a guiding roller (1), b) when viewed in cross section of the guiding roller (1), a blowout is formed; Claim (3) characterized in that the zone (B) is partly before and partly after the point where the drying plow net (49) reaches the guide roller (1). ~(
7) The guide roller according to any one of 7). (9) The guide roller according to claim (8), characterized in that the blowing zone (B) is smaller in the circumferential direction than the suction zone (S). (10) A closed zone ( The guide roller according to claim (8) or (9), characterized in that the guide roller is equipped with SZ). (11) The blockage zone (SZ) is located in the first cylinder (51
) to the second cylinder (52),
Guide rollers according to claim 10, characterized in that they are arranged at closer intervals. (12)a) A guide roller (1') is arranged between the first, second and third drying cylinders (51-53), and the drying material passes through these drying cylinders one after another. A paper web (50) to be dried runs and a drying screen (4
9) presses the paper web onto the first and third cylinders and between these cylinders a guiding roller (1'
b) the drying screen (49) runs with the paper web (50) from the first drying cylinder (51) to the guide roller (1'); c) the guide roller (1') When viewed in cross section, at least the main part of the suction zone (S) is covered by a drying screen (
49) is located before the point on the guide roller (1'), and the blowing zone (B) is located exclusively in the part of the circumference of the guide roller around which the drying screen (49) is wound. Claims (3) characterized in that:
) to (7), the guide roller according to any one of (Fig. 3)
. (13) The guide roller according to claim (12), characterized in that the suction zone (S) is smaller in the circumferential direction than the blowout zone (B). (14) A blockage, which is not connected to either of the two air chambers, between the suction zone (S) and the blowout zone (B) in the area where the drying screen (49) is wrapped around the guide roller (1') Guide roller according to claim 12 or 13, characterized in that it is provided with a zone (SZ). (15) The blowout zone (B) is almost completely covered by the guide roller (
1″) in the first quadrant wrapped around the drying screen (49) and an additional suction zone (S′) in the second quadrant wrapped around the drying screen (49) of the guiding roller. Claim (12) characterized in that:
The induction roller described in . (16) In the area where the drying screen (49) is wrapped around the guide roller (1″), between the blowing zone (B) and the additional suction zone (S′), it is connected to neither of the two air chambers. Guide roller according to claim (15), characterized in that it is provided with no additional closure zone (SZ').